The U.S. Pat. No. 5,374,040 discloses a vise which is composed of a rectangular base, two movable jaws, two transmission blocks, a control rod, a fixed jaw, a fitting tube, two end members, at least one elastic element, and a fastening block. Such a prior art vise as described above is limited in design in that the fastening block must be loosened each time when a work piece is to be worked on, and that the control rod is jutted out of the base, thereby causing a great deal of inconvenience to an operator.